xref: /openbmc/qemu/qobject/qjson.c (revision d1fd31f8)
1 /*
2  * QObject JSON integration
3  *
4  * Copyright IBM, Corp. 2009
5  *
6  * Authors:
7  *  Anthony Liguori   <aliguori@us.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
10  * See the COPYING.LIB file in the top-level directory.
11  *
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qapi/qmp/json-lexer.h"
17 #include "qapi/qmp/json-parser.h"
18 #include "qapi/qmp/json-streamer.h"
19 #include "qapi/qmp/qjson.h"
20 #include "qapi/qmp/qbool.h"
21 #include "qapi/qmp/qdict.h"
22 #include "qapi/qmp/qlist.h"
23 #include "qapi/qmp/qnum.h"
24 #include "qapi/qmp/qstring.h"
25 #include "qemu/unicode.h"
26 
27 typedef struct JSONParsingState
28 {
29     JSONMessageParser parser;
30     va_list *ap;
31     QObject *result;
32     Error *err;
33 } JSONParsingState;
34 
35 static void parse_json(JSONMessageParser *parser, GQueue *tokens)
36 {
37     JSONParsingState *s = container_of(parser, JSONParsingState, parser);
38 
39     s->result = json_parser_parse_err(tokens, s->ap, &s->err);
40 }
41 
42 QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp)
43 {
44     JSONParsingState state = {};
45 
46     state.ap = ap;
47 
48     json_message_parser_init(&state.parser, parse_json);
49     json_message_parser_feed(&state.parser, string, strlen(string));
50     json_message_parser_flush(&state.parser);
51     json_message_parser_destroy(&state.parser);
52 
53     error_propagate(errp, state.err);
54     return state.result;
55 }
56 
57 QObject *qobject_from_json(const char *string, Error **errp)
58 {
59     return qobject_from_jsonv(string, NULL, errp);
60 }
61 
62 /*
63  * IMPORTANT: This function aborts on error, thus it must not
64  * be used with untrusted arguments.
65  */
66 QObject *qobject_from_jsonf(const char *string, ...)
67 {
68     QObject *obj;
69     va_list ap;
70 
71     va_start(ap, string);
72     obj = qobject_from_jsonv(string, &ap, &error_abort);
73     va_end(ap);
74 
75     assert(obj != NULL);
76     return obj;
77 }
78 
79 typedef struct ToJsonIterState
80 {
81     int indent;
82     int pretty;
83     int count;
84     QString *str;
85 } ToJsonIterState;
86 
87 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
88 
89 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
90 {
91     ToJsonIterState *s = opaque;
92     QString *qkey;
93     int j;
94 
95     if (s->count) {
96         qstring_append(s->str, s->pretty ? "," : ", ");
97     }
98 
99     if (s->pretty) {
100         qstring_append(s->str, "\n");
101         for (j = 0 ; j < s->indent ; j++)
102             qstring_append(s->str, "    ");
103     }
104 
105     qkey = qstring_from_str(key);
106     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
107     QDECREF(qkey);
108 
109     qstring_append(s->str, ": ");
110     to_json(obj, s->str, s->pretty, s->indent);
111     s->count++;
112 }
113 
114 static void to_json_list_iter(QObject *obj, void *opaque)
115 {
116     ToJsonIterState *s = opaque;
117     int j;
118 
119     if (s->count) {
120         qstring_append(s->str, s->pretty ? "," : ", ");
121     }
122 
123     if (s->pretty) {
124         qstring_append(s->str, "\n");
125         for (j = 0 ; j < s->indent ; j++)
126             qstring_append(s->str, "    ");
127     }
128 
129     to_json(obj, s->str, s->pretty, s->indent);
130     s->count++;
131 }
132 
133 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
134 {
135     switch (qobject_type(obj)) {
136     case QTYPE_QNULL:
137         qstring_append(str, "null");
138         break;
139     case QTYPE_QNUM: {
140         QNum *val = qobject_to(QNum, obj);
141         char *buffer = qnum_to_string(val);
142         qstring_append(str, buffer);
143         g_free(buffer);
144         break;
145     }
146     case QTYPE_QSTRING: {
147         QString *val = qobject_to(QString, obj);
148         const char *ptr;
149         int cp;
150         char buf[16];
151         char *end;
152 
153         ptr = qstring_get_str(val);
154         qstring_append(str, "\"");
155 
156         for (; *ptr; ptr = end) {
157             cp = mod_utf8_codepoint(ptr, 6, &end);
158             switch (cp) {
159             case '\"':
160                 qstring_append(str, "\\\"");
161                 break;
162             case '\\':
163                 qstring_append(str, "\\\\");
164                 break;
165             case '\b':
166                 qstring_append(str, "\\b");
167                 break;
168             case '\f':
169                 qstring_append(str, "\\f");
170                 break;
171             case '\n':
172                 qstring_append(str, "\\n");
173                 break;
174             case '\r':
175                 qstring_append(str, "\\r");
176                 break;
177             case '\t':
178                 qstring_append(str, "\\t");
179                 break;
180             default:
181                 if (cp < 0) {
182                     cp = 0xFFFD; /* replacement character */
183                 }
184                 if (cp > 0xFFFF) {
185                     /* beyond BMP; need a surrogate pair */
186                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
187                              0xD800 + ((cp - 0x10000) >> 10),
188                              0xDC00 + ((cp - 0x10000) & 0x3FF));
189                 } else if (cp < 0x20 || cp >= 0x7F) {
190                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
191                 } else {
192                     buf[0] = cp;
193                     buf[1] = 0;
194                 }
195                 qstring_append(str, buf);
196             }
197         };
198 
199         qstring_append(str, "\"");
200         break;
201     }
202     case QTYPE_QDICT: {
203         ToJsonIterState s;
204         QDict *val = qobject_to(QDict, obj);
205 
206         s.count = 0;
207         s.str = str;
208         s.indent = indent + 1;
209         s.pretty = pretty;
210         qstring_append(str, "{");
211         qdict_iter(val, to_json_dict_iter, &s);
212         if (pretty) {
213             int j;
214             qstring_append(str, "\n");
215             for (j = 0 ; j < indent ; j++)
216                 qstring_append(str, "    ");
217         }
218         qstring_append(str, "}");
219         break;
220     }
221     case QTYPE_QLIST: {
222         ToJsonIterState s;
223         QList *val = qobject_to(QList, obj);
224 
225         s.count = 0;
226         s.str = str;
227         s.indent = indent + 1;
228         s.pretty = pretty;
229         qstring_append(str, "[");
230         qlist_iter(val, (void *)to_json_list_iter, &s);
231         if (pretty) {
232             int j;
233             qstring_append(str, "\n");
234             for (j = 0 ; j < indent ; j++)
235                 qstring_append(str, "    ");
236         }
237         qstring_append(str, "]");
238         break;
239     }
240     case QTYPE_QBOOL: {
241         QBool *val = qobject_to(QBool, obj);
242 
243         if (qbool_get_bool(val)) {
244             qstring_append(str, "true");
245         } else {
246             qstring_append(str, "false");
247         }
248         break;
249     }
250     default:
251         abort();
252     }
253 }
254 
255 QString *qobject_to_json(const QObject *obj)
256 {
257     QString *str = qstring_new();
258 
259     to_json(obj, str, 0, 0);
260 
261     return str;
262 }
263 
264 QString *qobject_to_json_pretty(const QObject *obj)
265 {
266     QString *str = qstring_new();
267 
268     to_json(obj, str, 1, 0);
269 
270     return str;
271 }
272